caccl-lti

LTI launch validator for IMS-LTI standard launches.

Usage no npm install needed!

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  import cacclLti from 'https://cdn.skypack.dev/caccl-lti';
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README

caccl-lti

Validates and parses LTI launch requests.

With caccl-lti, it's easy to enable LTI launches from Canvas. We'll take care of parsing and verifying the validity of launch requests.

Part of the CACCL library

Canvas
App
Complete
Connection
Library

Quickstart

Quickstart:

const initLTI = require('caccl-lti');

initLTI({
  app: /* express app with express-sessions enabled */,
  installationCredentials: /* { consumer_key, consumer_secret }*/,
});

The app will now be set up to accept LTI launches at /launch. See "Launch Parsing" below to find info on parsed launches.

Configuration Options

When initializing caccl-lti, you can pass in many different configuration options to customize caccl-lti's behavior or turn on/off certain functionality.

Note: configuration options are optional unless otherwise stated

Config Option Type Description Default/Required
app express app express app to add routes to Required
installationCredentials object LTI consumer credentials of form: { consumer_key, consumer_secret } Required
launchPath string path to accept launches at (new express POST route added) /launch
redirectToAfterLaunch string path to redirect to after successful launch same as launchPath
nonceStore NonceStore a nonce store to use for keeping track of used nonces memory store
disableAuthorizeOnLaunch boolean if false, redirects to authorizePath after launch is validated and parsed (and includes redirectToAfterLaunch) as the 'next link so that caccl-authorizer redirects to redirectToAfterLaunch after finishing authorization false
authorizePath string the authorization path (as set up by caccl-authorizer, required if disableAUthorizeOnLaunch is true null

Launch Parsing

Launches are automatically parsed and added to session. To retrieve launch info, see the req.session.launchInfo variable, which has the following properties:

For more detailed information, see Canvas' LTI documentation.

User Info

Property Type Description
userId number Canvas user id of the person who launched the app
userLoginId string Canvas login id (e.g., university id)
userEmail string the user's primary Canvas email (changeable in user's profile)
userFirstName string the user's first name
userLastName string the user's last name
userFullName string the user's full name
userImage string link to user's image
isInstructor boolean true if the user is an instructor in the launch course
isTA boolean true if the user is a teaching assistant in the launch course
isDesigner boolean true if the user is a designer in the launch course
isCreditLearner boolean true if the user is a for-credit learner (student) in the launch course
isNonCreditLearner boolean true if the user is a not-for-credit learner (student) in the launch course
isLearner boolean true if the user any type of learner (student) in the launch course
notInCourse boolean true if the user is not enrolled in the course
extRoles string[] list of extended Canvas roles
roles string[] list of basic Canvas roles (outdated)
locale string user locale (e.g., "en")

Launch Info

Property Type Description
timestamp number launch timestamp (ms)
contextId string LTI launch context
launchPresentationTarget string LTI launch presentation target (e.g., "iframe")
iframeWidth number iframe width (if applicable)
iframeHeight number iframe height (if applicable)
returnURL string LTI return URL
launchAppTitle string the title of the resource link (app title)
customParams object mapping (key => value) listing all custom launch parameters and their values

Course Info

Property Type Description
courseId number Canvas course id of the launch course
sisCourseId number Learning Information Services identifier for the course offering
enrollmentState string Canvas enrollment state (e.g., "active")

Canvas Info

Property Type Description
contextLabel string the name of the launch context (e.g., course name)
canvasHost string host of the launch Canvas instance
workflowState string Canvas workflow status (e.g., "active")